Thickness measurement system and method for vehicle occupant detection
First Claim
1. A vehicle passenger detection system for sensing a characteristic of a passenger in a passenger seating area, the system comprising:
- a vehicle seat having an outer surface adjacent to the passenger seating area;
a first electrode connected with a first portion of the vehicle seat a first distance from the outer surface;
a second electrode connected with the first portion of the vehicle seat at a second, different distance from the outer surface, the second electrode comprising a smaller area than the first electrode; and
a compressible insulator between the first and second electrodes.
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Accused Products
Abstract
A passenger detection system is provided. The passenger detection system utilizes an oscillation circuit that causes an antenna electrode to emit an electric field that is disrupted by the electrical characteristics of an object placed on the seat. This disruption alters the current and phase of the signal in the antenna electrode. By comparing the current flowing in the antenna electrode and/or the difference between the phase of the signal in the antenna electrode and the oscillation circuit output signal with predetermined threshold values, it is possible to detect the presence of a passenger in a reliable and inexpensive manner. The determination is made with a two layer electrode arrangement, including smaller and larger electrodes. The two layers allow calculation of an amount of compression on the seat. The amount of compression is used to characterize the passenger.
71 Citations
35 Claims
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1. A vehicle passenger detection system for sensing a characteristic of a passenger in a passenger seating area, the system comprising:
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a vehicle seat having an outer surface adjacent to the passenger seating area;
a first electrode connected with a first portion of the vehicle seat a first distance from the outer surface;
a second electrode connected with the first portion of the vehicle seat at a second, different distance from the outer surface, the second electrode comprising a smaller area than the first electrode; and
a compressible insulator between the first and second electrodes. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A vehicle passenger detection method for sensing a characteristic of a passenger in a passenger seating area, the method comprising the acts of:
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(a) connecting a first electrode to ground;
(b) measuring a first signal at a second electrode while the first electrode is connected to ground;
(c) electrically disconnecting the first electrode;
(d) measuring a second signal at the second electrode while the first electrode is electrically disconnected; and
(e) determining the characteristic of the passenger in a vehicle seat as a function of the first and second signals. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22)
(f) sequentially measuring third and fourth signals from at least third and fourth electrodes, respectively;
wherein (e) comprises determining the characteristic as a function of the first, second, third and fourth signals.
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19. The method of claim 18 wherein at least one of the second, third and fourth electrodes is spaced a different distance from an outer surface of the passenger seat than the others of the second, third and fourth electrodes.
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20. The method of claim 15 further comprising:
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(f) determining a distance between the first and second electrodes as a function of the first and second signals;
wherein the first and second electrodes are separated by a compressible insulator and (e) comprises determining a weight as a function of the distance.
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21. The method of claim 15 wherein (e) comprises determining a weight of the passenger.
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22. The method of claim 21 further comprising:
(f) controlling activation of an airbag in response to the weight.
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23. A vehicle passenger detection method for sensing an effect of a passenger in a passenger seating area, the method comprising the acts of:
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(a) connecting a first electrode to ground;
(b) measuring a first signal at a second electrode while the first electrode is connected to ground, the second electrode separated from the first electrode by a compressible insulator in a vehicle seat;
(c) determining a distance between the first and second electrodes as a function of the first signal. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
(d) determining a characteristic of the passenger as a function of the distance.
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25. The method of claim 24 wherein (d) comprises determining a distance of the passenger away from the vehicle seat.
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26. The method of claim 24 wherein (d) comprises determining a load of the passenger.
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27. The method of claim 24 wherein (d) comprises determining a weight of the passenger.
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28. The method of claim 23 further comprising:
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(d) electrically disconnecting the first electrode from ground;
(e) measuring a second signal at the second electrode while the first electrode is disconnected from ground; and
(f) determining a characteristic of the passenger as a function of the second signal and the distance.
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29. The method of claim 28 further comprising:
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(g) measuring a third signal at a third electrode, the third electrode separated from the second electrode by the compressible insulator;
wherein (f) comprises determining the characteristic as a function of the second and third signals and the distance.
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30. The method of claim 23 further comprising:
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(d) electrically disconnecting the first electrode from ground; and
(e) measuring a second signal at the second electrode while the first electrode is disconnected from ground;
wherein (c) comprises determining the distance as a function of the first and second signals.
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31. The method of claim 27 further comprising:
(e) controlling activation of an airbag as a function of the weight.
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32. The method of claim 23 further comprising:
(d) determining a second distance between a third electrode and a fourth electrode.
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33. The method of claim 32 further comprising:
(e) determining first and second load characteristics of the passenger as a function signals from the second and third electrodes, respectively, and the first and second distances, respectively.
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34. A vehicle passenger detection system for sensing a characteristic of a passenger in a passenger seating area, the system comprising:
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an compressible insulator;
a plurality of electrodes arranged in at least two layers, the electrodes of one of the at least two layers separated from the electrodes of another of the at least two layers by the compressible insulator;
a switch for connecting at least one the plurality of electrodes to ground; and
a controller operable to determine a distance between the at least two layers as a function of information received from a first of the plurality of electrodes while a second of the plurality of electrodes is grounded. - View Dependent Claims (35)
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Specification